Co-occurrence of SLC7A7 mutation with a novel PACS2 variant in a child with lysinuric protein intolerance: expanding the clinical spectrum

Abstract

Lysinuric protein intolerance (LPI) is a rare, autosomal recessive metabolic disorder caused by mutations in the SLC7A7 gene, leading to defective transport of cationic amino acids. It typically presents with vomiting, failure to thrive, hepatosplenomegaly, protein intolerance, hyperammonaemia, pulmonary and renal systems. Separately, heterozygous pathogenic variants in the PACS2 gene have been associated with early-onset developmental and epileptic encephalopathy (DEE66), marked by hypotonia, drug-resistant seizures, and global developmental delay, encephalopathy. We report a 7-month-old male child whose initial presentation was persistent vomiting, developmental delay, poor weight gain, hypotonia, seizures, and acute encephalopathy. The patient required mechanical ventilation for a month and was subsequently discharged on syrup levetiracetam, benzoate citrulline, arginine and supportive care.